

598 Mr. T. Smith on certain Species of Car dims and Cnicus 



I have looked over the specimens of Cardans and Cnicus in 

 the Banksian Herbarium, and the following appear to be female 

 plants : 



Carduus rivularis, Chius, rigens, serratuloides, paniculatus. Cni- 

 cus ieucocephalus, rigens, Erisithales, tuberosus, acaulis, oleraceus. 



There are specimens of both sexes of Erisithales and acaulis ; 

 the specimen of the female plant of acaulis is remarkably distinct 

 from the male. 



Since I first turned my attention to this subject, a doubt has 

 arisen whether in many, perhaps in most of the cases in which 

 female plants occur, the antheriferous plant may not be an her- 

 maphrodite rather than a male. 



The plant which I first ascertained to be dioecious was Cnicus 

 arvensis : in this the separation of the sexes is undoubted and 

 unequivocal ; for though I have examined a very great number 

 of male plants, the ovaria have always proved abortive, except 

 in one instance, in which two of the ovaria in one capitulum were 

 most decidedly impregnated, the embryo being so far advanced 

 that no doubts could be entertained about it : the stigmata of 

 these flowers did not, however, appear to differ from those of the 

 numerous unimpregnated ovaria which surrounded them: this 

 case must therefore be considered as merely accidental. 



Having ascertained that this species was dioecious, I con- 

 cluded that all the others were so in which female plants were to 

 be met with ; but, in some, hermaphrodite plants certainly occur, 

 nor have I been able to detect any males amongst these. It is not 

 easy to distinguish between the hermaphrodite and the male ; the 

 only unequivocal test of the latter seems to be, that the antherce 

 should have perfect pollen, and that the ovaria should be abor- 

 tive ; two states of the flowers which it is rather difficult to meet 

 with on the same plant at the same time. 



The stigma does not supply a distinction sufficiently decisive ; 



for 



